Pneumatic action for musical instruments.



P. I. BURKS.

PNEUMATIC ACTION FOR MUSIGAL INSTRUMENTS.

APPLICATION FILED SEPT.24, 1913.

1,105,248, Patented July 28, 1914.

2 SHEETS-SHEET 1.

un/Mum THE NORRIS PETERS CO.. PHUTO-LI'IHO. WASHINGTON. D. C.

P. 1. BURKS.

PNEUMATIC ACTION FOR MUSICAL INSTRUMENTS.

APPLICATION IILED' SEPT. 24, 1913. 1,105,248, Patented July 28, 1914.

' 2 SHEETSSHEET 2.

70 v/ 1 l l\ \x 19 26 z z a 0 2.9 1/ A,

E Emiflf 52 (3'5 7 0 52 THE NORRIS PETERS (O.. PHOTO-LI'IHQ. WASHINGTON. O, C.

the bleeder passages, etc.

UNITED STATES PATENT ()FFICE.

7 PAUL I. BURKS, OF LOUISVILLE, KENTUCKY.

PNEUMATIC To all whom it may concern:

Be it known that 1, PAUL I. BURKS, a citizen of the United States, residing at Louisville, in the county of Jefierson and State of Kentucky, have invented new and useful Improvements in Pneumatic Actions for Musical Instruments, of which the following is, a specification.

The present invention relates to pneumatic piano players, and particularly to the pneumatic action of such players.

It has for its object to provide an action in which the number of parts are few and so designed as to lend themselves readily to economical manufacture and assembly of the action, the passages being so arranged as that a strong and tight structure will be provided, and one in which danger of derangement of the parts or leakage will be minimized.

In order that the construction may be understood by those skilled in the art, I have illustrated in the drawings one embodiment of my invention, although it will be understood that the construction may be varied considerably from the particular dis closure herein without departing from the spirit of my invention.

In the drawings,-Figure 1 is a sectional view transversely of the action. Fig: 2 is a longitudinal view of a portion of the action on the line 2-2 of Fig. 1. Fig. 8 is a longitudinal section on the line 3-3 of Fig. 1. Fig. 4: is a longitudinal section on the line 4 1 of Fig. 1. Fig. 5 is a plan view of the valve board to show the valve seats and suction passages leading to the key-operating pneumatics. Fig. 6 is a plan view of the tracker duct board to show the valve supporting diaphragms and Fig. 7 is a detail enlarged elevation of the valve.

Referring to the drawings by numerals, like numbers indicating like parts in the several views, and referrings first to Fig. 1, it will be observed that the action is made up of three sections or boards, as shown in the present disclosure.

The main board or section 10 is provided with the vacuum passage or channel 11 adapted to be connected with any suitable exhaust device (not shown) which will maintain the same under vacuum of whatever tension may be desired, the said passage 11 being cut in the under side of the board 10 and running longitudinally Specification of Letters Patent. AppIication filed September 24, 1913.

ACTION FOR MUSICAL INSTRUMENTS.

Patented July 28, 1914.

Serial No. 791,447.

thereof. Parallel with said passage 11, and separated therefrom by a wall 12 is a second passage 13, which is the bleeder passage of the action, and, as is customary, is under vacuum tension, said bleeder passage 13 connecting through a perforation 141 in a suitable diaphragm with the tracker duct 15 formed in an independent section or board 16, and thence by the tracker tube 17 with the usual tracker board (not shown).

The wall 12 is solid or imperforate to entirely cut ofi? the bleed passage 11 from the main channel 11 so that change in vacuum tension in the main passage will not affect the vacuum tension in the bleed passage, and is located between the main channel and the bleed passage for the purpose of reinforcing the middle section and producing a compact rigid structure.

The tracker duct 15 communicates by a passage 18 with the chamber or passage 11, but is separated therefrom by a diaphragm 19 which carries the valve lifting pad 20, as shown in Figs. 1 and 2.

IVith this construction it will be seen that during the operation of the player with both the chambers 11 and 13 and the tracker duct 15 and tube 17 which are connected through the perforation 141 with the bleeder channel 13, under vacuum tension that a condition of vacuum will exist throughout the action, and the parts thus far described will be in the position shown in Figs. 1 and 2 with the diaphragm 19 in its lower full-line position. The said diaphragm 19 and its supporting block or pad 20 carries the valve 21, the stem 22 of which is cushioned at its lower end 23, which rests upon the block 20, this insuring elimination of any objectionable clicking due to the impact of the valve stem 22 and the diaphragm pad 20. The valve 21 rests upon a valve seat 2 1 formed in the wood of the section or board 10, said valve seat and its surrounding chamber 25 in which the valve 21 plays being shellacked and burnished so as to give a smooth, finished surface which will not interfere with the movements or seating of the valve 21 and yet which will not wear unduly the leather face 26 of the valve 21, thereby prolonging its life and usefulness.

The valve body 21, as shown is formed of wood with a wooden stem which, as stated, is cushioned at its lower end and both the upper and lower surfaces of the valve, as

upper wall of said shown in Fig. 7, are faced with leather or Y other suitable material, as indicated at 26 and 27, and preferably, in order to give a properly cushioned face to the valve, I interpose between the leather facing 26 on the lower side of the valve and the valve body a cushion 28 of felt or other suitable material, this construction insuring a proper grip and seating of the valve upon the wooden seat 2 1.

The valve body 21 will be shellacked and burnished, as indicated, so that an exterior devoid of any roughness which would interfere with the action of the valve or the passage of air currents with any attendant hissing or whistling is avoided. In other words, a perfectly smooth valve chamber and valve are provided by this burnishing down of the wooden valve and valve seats, and the objectionable features of metallic seats and valves which are subject to corro: sion and consequent imperfect action is done away with.

In order to guide the valve 21 in its movements the stem 22 passes through a strip 29, preferably of wood, which runs longitudinally of the passage 11, being offset from the passage by the blocks 30 arranged at intervals, this offsetting of the guiding strip 29 furnishing a clear passage between the chamber or passage 11 and the port 31 which connects said passage 11 with the valve chamber.

The valve chambers connect by the horizontal passages 32 with the vertical pneumatic passages 33, which lead through the boards 10 and 16 and are in register, the passages 33 at their lower ends connecting each with their respective pneumatics 34:,

which pneumatics are provided, as is usual, with the tappet fingers 35 adapted to operate on the key-actuating rods 36 in the well known manner.

In order to insure a proper outlet from the passage 11 beneath the valve 21 to the pneumatic passages 32, I preferably enlarge the valve chambers by means of semi-circiu lar cut-outs 37, thus insuring a sufficient area to prevent choking when the valves 21 lift and throw the vacuum passage 11 into communication with the pneumatics 34L.

Surmounting the valve section or board 10 is a top section or board 38 which is provided with atmospheric openings 39 to normally maintain th pneumatics 341 under atmospheric condition, and, as shown in Fig. 1, distend the pneumatics these atmospheric openings 39, being in line with the valves 21, so that when the valves lift their upper cushioned faces will seat against and close the openings 39 and prevent interference with the vacuum tension existing in the chamber 11, passages 32, and pneumatic passages 33.

The three sections or boards of the action are preferably of the same dimensions as to length and width, and are held together by suitable through fastenings, as screws, 40, and in order to insure tight joints, I preferably interpose between the boards or sections the packing material 41, preferably of leather, and which when the fastenin devices 40 are set up will be compresse and furnish absolutel tight joints between all of the members.

The diaphragms 19 may, of course, be constructed in any suitable way, but I have found a very feasible plan to be the provision of a strip 42 of parchment or paper of suflicient strength which is fastened by a suitable adhesive over the line of openings 18 in the lower board 16, there being centrally placed relative to the opening 16 the blocks 20 of cardboard or other like material, these being secured by a suitable adhesive to the parchment strip 42, and thereby a very light and quickly responsive diaphragm is provided.

I claim 1. In a pneumatic valve action, the combination of a base section provided with a tracker-duct and a depression communicating with said tracker-duct, a diaphragm extending over said depression, an intermediate section having its under-face provided with a main suction channel located over said diaphragm, and having a valve chamber formed in its upper face communicating with said channel by means of an openin forming a valve seat, a "alve within sai chamber and supported by said diaphragm to eoa'ct with said valve seat, the under-face of said intermediate section being further provided with a bleed channel communicating with said tracker-duct of said base section, and a top section placed over said intermediate section, and provided with an opening o er said valve.

2. In a pneumatic valve action, the combination of a base section provided with a tracker-duct and a depression communieating with said tracker-duct, a diaphragm extending over said depression, an intermediate section having its under-face cut away to provide a main suction channel located over said diaphragm and having a valve chamber formed in its upper face and communicating with said channel, a valve seat formed integral with the bottom wall of said chamber, a valve within said chamber and supported by said diaphragm to coact with said valve seat, the under-face of said intermediate section being further provided with a. bleed channel communicating with said tracker-duct of said base section and imperforate with respect to said main suction channel, and a top section placed over said intermediate section and provided with an opening over said valve.

3. In a pneumatic valve action, the combination of a base section, provided with a tracker-duct and a depression communieating with said tracker-duct, a diaphragm extending over said depression, a pneumatic carried upon the lower face of said base section, said base being further provided with a vertical passage communicating with said pneumatic, an intermediate section having its under face cut away to provide a main suction channel located over said diaphragm and having a valve chamber formed in its upper face and communicating with said channel, a valve seat formed integral with the bottom wall of said chamber, a valve within said chamber and supported upon said diaphragm and coacting with said valve seat, said intermediate section being provided with a vertical passage communieating with said passage of said base section, the under face of said intermediate section being further provided with a bleed channel intermediate of said suction chamber and said vertical passage communicating with said tracker-duct of said base section, said bleed chamber being free from communication with said suction chamber, the upper face of the intermediate section being provided with a longitudinally extending passage connecting said first-mentioned vertical passages with said valve chamber, and a top section placed over said intermediate section and provided with an opening over said valve and communicating with said longitudinal passage.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

PAUL I. BURKS.

Witnesses:

Jim. W. REA, D. T. MITCHELL.

Copiel of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0. 

